Say "sendKeys()" method is sending text to a webelement .This method can be used with textboxes but we can't use it on images , links. These are all basic things which we will learn through experience.

Here are the samples , on how to achieve basic functionality of different webelements using webdriver functions:

Textboxes :Send text
Sending text to Textboxes can be done by using "sendKeys()" method. Here is how it works:

driver.findElement(By.id("textBoxId")).sendKeys("sending text");

RadioButtons :Select an option
Selecting an option from Radio button can be done by using "click()" method.Here is how it works:

driver.findElement(By.id("radioButtonId")).click();

Hyperlinks :Click on links
Clicking on link can be done by using "click()" method.Here is how it works:

driver.findElement(By.id("linkId")).click();

Checkboxes :Check the checkboxes
Selecting options from Checkboxes can be done by using "click()" method.Here is how it works:

driver.findElement(By.id("checkBoxId")).click();

Drop-down List :Select an option
Selecting an option from Dropdown list can be done by using "sendKeys()" method.Here is how it works: